1. Field of the Invention
The present invention relates to a recording-medium cartridge loading device, and, in particular, to a recording-medium cartridge loading device which has an arrangement such that a loading operation of a recording-medium cartridge is performed only when the recording-medium cartridge containing a recording medium is inserted in the correct orientation.
2. Description of the Related Art
For example, an electronic apparatus, such as a personal computer, a word processor or the like, is equipped with a magnetic disk device as means for recording information. In the magnetic disk device, when a disk cartridge (recording-medium cartridge) containing a magnetic disk as a recording medium is loaded, the magnetic disk contained in the disk cartridge is driven and rotated, and, also, magnetic heads slide on the magnetic disk so that magnetic recording and reproducing are performed.
Further, in the magnetic disk device, a head carriage which supports the magnetic heads moves in a radial direction of the magnetic disk along a guiding shaft so that the magnetic heads are caused to slide on an arbitrary recording track of the magnetic disk, and magnetic recording or reproducing is performed.
Further, in the magnetic disk device, as a result of disk rotation speed being increased, the recording medium is made to have a high density, and the storage capacity of the magnetic disk is increased. In such a kind of large-capacity magnetic disk device, because a floating force occurring due to air flow resulting from high-speed rotation of the magnetic disk is applied to the magnetic heads, the magnetic recording and reproducing can be performed in a condition in which the magnetic heads slightly float from the surfaces of the magnetic disk.
There are a plurality of types of disk cartridges which have different storage capacities. Corresponding to storage capacities of disk recording media, a double-sided double-density double-track disk (generally called `2DD`) and a double-sided high-density double-track disk (generally called `2HD`) have been standardized.
Further, recently, a disk recording medium having a storage capacity larger than the 1.44-MB storage capacity of the 2HD has been developed. For example, there is a disk cartridge (generally called `HiFD`) having a storage capacity of 240 MB in an unformatted condition and having a storage capacity of 200 MB in a formatted condition.
The conventionally used low-capacity cartridge (2DD or 2HD), and the high-capacity cartridge (HiFD), having the large storage capacity, are formed to have respective dimensions approximately identical and have respective outer shapes approximately identical, so as to be compatible. There is a magnetic disk device which can perform magnetic recording or reproducing when any type of cartridge, i.e., the low-capacity cartridge (2DD or 2HD) or the high-capacity cartridge (HiFD), is inserted.
In a conventional magnetic disk device widely used in a personal computer or the like, any of the low-capacity cartridges, i.e., 2DD and 2HD, can be loaded. However, because formats of the magnetic disks 2DD and 2HD are different, the magnetic disk device should determine whether a loaded disk cartridge is 2DD or 2HD. For this purpose, a detecting switch for detecting 2DD is provided in the magnetic disk device. When this detecting switch is in an ON condition, it is determined that the loaded disk cartridge is 2DD. When the detecting switch is in an OFF condition, it is determined that the loaded disk cartridge is 2HD.
In a magnetic disk device in which the high-capacity cartridge is loaded, the low-capacity cartridge can also be loaded.
As described above, these disk cartridges have different storage capacities but have approximately identical outer shapes and approximately identical dimensions of respective portions. However, because the storage capacity of the magnetic disk of the high-capacity cartridge is larger than that of the magnetic disk of the low-capacity cartridge, the rotation speed of the magnetic disk of the high-capacity cartridge is higher than that of the magnetic disk of the low-capacity cartridge, for example, and also, the magnetic heads and the head carriage are designed differently for the HiFD.
FIG. 1 shows a perspective view indicating the shape of the 2HD cartridge.
The 2HD cartridge 100 contains a magnetic disk. As shown in FIG. 1, a shutter 102 for uncovering and covering an opening 101 through which the magnetic heads (not shown in the figure) approach the disk is slideably provided at the front end in the inserting direction of the cartridge 100.
At the corner at the right side of the front end of the cartridge 100, a cut-off portion 103, which is inclined at 45.degree. with respect to the inserting direction, is provided. This cut-off portion 103 engages with an erroneous-insertion preventing mechanism provided in a below-described recording-medium cartridge loading device (hereinafter, referred to as a `loading device`) and causes this mechanism to enable a cartridge inserting operation.
That is, when the inserting direction of the cartridge 100 is erroneous, because the cut-off portion 103 is located at a position such as not to engage with the erroneous-insertion preventing mechanism, insertion of the cartridge is prevented. At the rear side of the cartridge 100, a write protect 100a for inhibiting writing and an opening 100b for identifying that this cartridge is a 2HD cartridge are provided.
The 2DD cartridge has dimensions the same as the dimensions of the above-described 2HD cartridge 100 and a shape the same as the shape of the above-described 2HD cartridge 100 except that the opening 100b for 2HD identification is not provided in the 2DD cartridge.
FIG. 2 shows a perspective view indicating the shape of the HiFD cartridge.
The HiFD cartridge 105 has dimensions the same as those of the 2HD cartridge 100 and a shape approximately the same as the shape of the 2HD cartridge 100. As shown in FIG. 2, a shutter 107 for uncovering and covering an opening 106 through which the magnetic heads (not shown in the figure) approach the disk is slideably provided at the front end in the inserting direction of the cartridge 105.
Further, at the front end in the inserting direction, a cut-off portion 108 having a shape of a groove extending in the inserting direction is provided. This cut-off portion 108 is different from the cut-off portion 103 of the above-described 2HD cartridge 100. Therefore, in a loading device designed specifically for 2DD or 2HD, the HiFD cartridge 105 cannot be loaded.
A loading device, in which any of the 2HD cartridge 100, the 2DD cartridge and the HiFD cartridge 105 can be loaded, has an arrangement such that erroneous insertion of the cartridge 100 or 105 can be prevented as a result of any one of the cut-off portion 103 and the cut-off portion 108 being detected. In the HiFD cartridge 105, an opening 105a, a write protect 105b for inhibiting writing and an opening 105c for identifying that this cartridge is an HiFD cartridge are provided.
The loading device in which any one of the 2DD, 2HD and HiFD cartridges can be loaded will now be described.
FIG. 3 shows a plan view of a magnetic disk device in which any one of the 2DD, 2HD and HiFD cartridges can be loaded.
As shown in FIG. 3, in the magnetic disk device 110, a loading device 111 in which any one of the three types of disk cartridges, i.e., 2DD, 2HD and HiFD, (not shown in the figure) can be loaded is provided above a chassis 112. The loading device 111 has a disk holder 113 in which the disk cartridge (not shown in the figure) is inserted.
Further, at the front surface of the chassis 112, a bezel 115 having a disk inserting hole and an ejecting button 114 is mounted. Further, below the disk holder 113, a slider 116 which lifts and lowers the disk holder 113 while performing a sliding operation is provided.
The disk holder 113 has disk insertion guides 113a and 113b which are formed so as to define a space in which the disk cartridge is inserted. An insertion position of the disk cartridge 100 or 105 is guided as a result of the both sides of the cartridge sliding on the disk insertion guides 113a and 113b, respectively.
At a rear portion of a top plate of the disk holder 113, an erroneous-insertion preventing mechanism 130 is provided. The erroneous-insertion preventing mechanism 130 includes a lever 132, which is rotatably supported by a shaft 131 which stands at a rear portion of the top plate of the disk holder 113, and a coil spring 133 which applies force to the lever clockwise. The lever 132 is provided with an engagement portion 134 which engages with the cut-off portion 103 or 108 of the cartridge 100 or 105, the engagement portion 134 being bent downward.
At the center of the rear portion of the disk holder 113, a head carriage 117 which supports magnetic heads, and a carriage driving mechanism 118 which drives the head carriage 117 are provided. The carriage driving mechanism 118 includes a guiding shaft 119 which guides the head carriage 117, a leading screw 120, and a carriage driving motor 121 which rotates the leading screw 120 and thus moves the head carriage 117.
At the right side of the rear portion of the disk holder 113, a latch lever 122 is rotatably provided. The latch lever 122 engages with and prevents movement of a slider (not shown in the figure) when the disk cartridge is ejected, and pushes the disk cartridge 100 or 105, inserted in the disk holder 113, in the ejecting direction when an ejection operation is performed. That is, the latch lever 122 is mounted on the chassis 112 and can rotate about a rotation shaft 122a, and has a force applied thereto in the ejecting direction (counterclockwise) by a torsion spring (not shown in the figure). The latch lever 122 stops engagement with and prevents movement of the slider as a result of insertion of the disk cartridge.
The ejecting button 114 is coupled to the front end of the slider and, when the ejecting button 114 is pushed, the slider slides to a position at which the slider stops engagement with and prevents movement of the latch lever 122. Thereby, the latch lever 122 pushes the disk cartridge and the disk cartridge 100 or 105 is ejected through the disk inserting hole of the bezel 115.
On the chassis 112, a turntable 124 and a disk motor 125 are provided. The turntable 124 drives and rotates the magnetic disk of the disk cartridge 100 or 105, which has been held at a loading position through falling of the disk holder 113. The disk motor 125 drives and rotates the turntable 124.
The above-mentioned erroneous-insertion preventing mechanism 130 has an arrangement such that the engagement portion 134 of the lever 132 provided at the rear portion of the top plate of the disk holder 113 engages the cut-off portion 103 or 108 of the cartridge 100 or 105, and, thus, insertion of the cartridge 100 or 105 is enabled.
FIGS. 4A, 4B and 4C illustrate an operation of the erroneous-insertion preventing mechanism 130.
When, as shown in FIG. 4A, the high-capacity (HiFD) cartridge 105 is inserted in a condition where the top and the bottom of the cartridge are inverted, the cut-off portion 108 cannot engage with the engagement portion 134, and the front end in the inserting direction of the high-capacity cartridge 105 comes into contact with an end of the engagement portion 134. Thereby, the high-capacity cartridge 105 cannot be inserted, and, thus, erroneous insertion is prevented.
When, as shown in FIG. 4B, the high-capacity cartridge 105 is inserted in the correct orientation, the engagement portion 134 is fitted into the groove of the cut-off portion 108, and, thereby, insertion of the high-capacity cartridge 105 is enabled. As a result, the high-capacity cartridge 105 is loaded in a predetermined loading position.
When, as shown in FIG. 4C, the low-capacity (2HD) cartridge 100 is inserted in the correct orientation, the engagement portion 134 engages with the inclined surface of the cut-off portion 103, and the lever 132 rotates counterclockwise. Thus, the engagement portion 134 retreats from the path through which the low-capacity (2HD) cartridge 100 is inserted. Thereby, insertion of the low-capacity cartridge 100 is enabled. As a result, the low-capacity cartridge 100 is loaded in the predetermined loading position.
However, because the lever 132 of the erroneous-insertion preventing mechanism 130 is provided at the top plate of the rear portion of the disk holder 113, when the low-capacity cartridge 100 or the high-capacity cartridge 105 is inserted into the disk holder 113 in an erroneous orientation, the end of the engagement portion 134 comes into contact with the insertion-side end of the cartridge, after the cartridge 100 or 105 is inserted to a stage immediately before the insertion into the disk holder 113 is finished, and, then, insertion of the cartridge 100 or 105 is prevented.
Therefore, whether or not the orientation of the cartridge 100 or 105 is correct cannot be determined until the cartridge 100 or 105 is almost completely inserted into the disk holder 113. Thus, it is not possible to determine the orientation of the cartridge 100 or 105 in an initial stage of insertion of the cartridge.
Further, in the magnetic disk device in the related art, as shown in FIG. 3, the latch lever 122 provided on the chassis 112 and the erroneous-insertion preventing mechanism 130 provided at the top plate of the disk holder 113 are located at the same position on the plan view. Because the latch lever 122 and the erroneous-insertion preventing mechanism 130 thus overlap each other on the plan view via the disk holder 113, it is difficult to reduce the thickness of the device.